Key takeaways:
Astigmatism develops because the cornea or the lens of the eye changes shape.
Astigmatism causes blurred or distorted vision, eyestrain, and headaches.
Treatment with eyeglasses, contact lenses, or surgery can relieve astigmatism.
Vision changes are one of those things you should never ignore. Blurry vision is a common sign of eye conditions — from common ones, like cataracts, to serious conditions, like retinal detachment.
One of the most common reasons for blurry vision is a refractive error. Most people recognize refractor errors like myopia (nearsightedness) and hyperopia (farsightedness). But fewer people are familiar with astigmatism.
Astigmatism is also a refractive error that people tend to develop as they get older. So if you’ve recently been diagnosed with astigmatism, here’s how to get your vision back in focus.
Astigmatism develops when either the cornea or lens of the eye changes shape.
The eyeball should be shaped like a sphere. An astigmatism causes the eye to be the shape of an oval or football. This change can happen naturally as you get older. You can also be born with astigmatism.
When the cornea or lens is not evenly curved, light entering the eye bends the wrong way. Normally, light enters the eye and hits the retina (the back layer of the eye). The retina converts light signals into electrical signals and then passes these signals to the brain so you can see.
If you have a refractive error, like an astigmatism, the light hitting your retina is bent out of shape. Your retina passes on these distorted light signals to your brain. So you see images that look blurry or distorted.
Yes, you can develop astigmatism as you get older. A study showed that 1 in 4 people between 25 and 59 years old had astigmatism. But in people over the age of 60, that number doubles to 1 in 2 people. This happens because the shape of the cornea and lens can change as you age.
You can also develop astigmatism after eye surgery or eye trauma. Some eye conditions can also cause it, especially keratoconus (a genetic condition).
Some people don’t have any symptoms from their astigmatism. If there’s only a slight change in the eye’s shape, you might not experience any vision changes.
But if you have a moderate or severe astigmatism, you’ll notice symptoms like:
Blurry vision
Trouble seeing at night
Headaches
Squinting
Your eye doctor can diagnose astigmatism during an eye exam. First you’ll read an eye chart. Then they’ll ask you to read the eye chart while looking through different strength lenses. Your ability to see the eye chart more clearly with lenses allows the eye doctor to figure out if you have an astigmatism (or another refractive error).
Your eye doctor may also use specialized equipment to help diagnose refractive errors like keratometry and corneal topography. These tests are not painful.
Anyone who has vision changes from an astigmatism needs treatment. You should also get treatment if you have headaches or eyestrain — even if your vision changes are less bothersome.
Young children should always get treatment for astigmatism, even if it’s mild. In young children, untreated astigmatism can lead to amblyopia, which can cause permanent vision loss.
Options to treat astigmatism include:
Eyeglasses: Eyeglasses are a safe way to treat astigmatism. They’re also the most cost-effective option. But sometimes glasses can’t completely correct astigmatism.
Contact lenses: Soft toric contact lenses can fully correct astigmatism. Toric contact lenses have a special shape that specifically corrects astigmatism. If you have a high amount of astigmatism, your doctor may recommend a rigid gas-permeable lens, a special type of contact lens.
Refractive surgery: Refractive surgery, like LASIK, treats certain types of astigmatism. During LASIK, a laser reshapes the cornea so light enters the eye correctly. Refractive surgery isn’t right for everyone. If you have keratoconus, refractive surgery can worsen your vision.
If you need cataract surgery, your surgeon can correct your astigmatism at the same time. You can either opt for a special type of intraocular lens or your surgeon can reshape your cornea by making precise incisions while removing your lens.
Some people are interested in more natural ways to correct their astigmatism. Right now, there’s no evidence that vitamins or eye exercises can correct astigmatism.
Astigmatism is a type of refractive error that causes blurry and distorted vision. People can be born with astigmatism or develop it over time, especially as they get older. If you notice symptoms of astigmatism, be sure to visit your eye doctor. Treatment for astigmatism includes glasses, contacts, or refractive surgery.
Boyd, K. (2022). What is Astigmatism? Symptoms, causes, diagnosis, treatment. American Academy of Ophthalmology.
Boyd, K. (2022). What is keratoconus? American Academy of Ophthalmology.
Lazarus, R. (2021). Astigmatism: Top 9 FAQs. Optometrists Network.
National Eye Institute. (2022). How the eyes work.
Vitale, S., et al. (2008). Prevalence of refractive error in the United States, 1999-2004. JAMA Ophthalmology.